A versatile proximity-dependent probe based on light-up DNA-scaffolded silver nanoclusters

It is well-known that proximity-dependent probes containing an analyte recognization site and a signal formation domain could be assembled specifically into a sandwich-like structure (probe-analyte-probe) via introducing an analyte. In this work, using the design for zirconium ion (Zr4+) detection as the model, we develop a novel and reliable proximity-dependent DNA-scaffolded silver nanocluster (DNA/AgNC) probe for Zr4+ detection via target-induced emitter proximity. The proposed strategy undergoes the two following processes: target-mediated emitter pair proximity as target recognition implement and the synthesis of DNA/AgNCs with fluorescence as a signal reporter. Upon combination of the rationally designed probe with Zr4+, the intact templates were obtained according to the -PO32--Zr4+-PO32- -pattern. The resultant structure with an emitter pair serves as a potent template to achieve highly fluorescent DNA/AgNCs. To verify the universality of the proposed proximity-dependent DNA/AgNC probe, we extend the application of the proximity-dependent probe to DNA and adenosine triphosphate (ATP) detection by virtue of a specific DNA complementary sequence and ATP aptamer as a recognition unit, respectively. The produced fluorescence enhancement of the DNA/AgNCs in response to the analyte concentration allows a quantitative evaluation of the target, including Zr4+, DNA, and ATP with detection limits of similar to 3.00 mu M, similar to 9.83 nM, and similar to 0.81 mM, respectively. The proposed probe possesses good performance with simple operation, cost-effectiveness, good selectivity, and without separation procedures.